The Nube dwarf galaxy (center) has an unusually low concentration of stars that does not fit with our understanding of the universe. (Image credit: GTC/Mireia Montes)

Scientists have discovered an "almost invisible" dwarf galaxy that cannot be explained by our current understanding of the cosmos. The mysteriously faint object, which has evaded detection for years, is so dim that researchers haven't even been able to pin down exactly where it is.

The newfound galaxy, named Nube (or "cloud" in Spanish), was described in a study published Jan. 9 in the journal Astronomy & Astrophysics. Nube is extremely diffuse, which means that its stars are very spread out and, as a result, the galaxy emits barely any light. It is around 10 times fainter than most other known dwarf galaxies and is more than 10 times wider than it should be considering the number of stars it has.

"With our present knowledge we do not understand how a galaxy with such extreme characteristics can exist," study lead author Mireia Montes, an astrophysicist at the Institute of Astrophysics of the Canary Islands, said in a statement.

The researchers discovered Nube when they reanalyzed data collected by the Sloan Digital Sky Survey — one of the largest and most detailed astronomical databases of the night sky — and spotted a small inconsistency that had gone unnoticed for years. After catching the anomaly, the team took ultra-deep multicolor images of the outlying coordinates using the Green Bank Telescope in West Virginia and the Gran Telescopio Canarias in La Palma, Spain.

But even then, Nube is so faint that the team cannot accurately pin down its exact distance from our own galaxy. The researchers suspect that it is around 300 million light-years from the Milky Way, and around a third of the size across, but further observations are needed to confirm this.  ...

 

Had a delightful, silly, brilliant, bizarre, expensive-looking black street rescue kitty whom I named Anubis w/in 20 mins of our meeting.   Our beasties always have many nicknames, and a few of hers included Anubie, Nubie, and Nube {but pronounced ‘noob’}.  Hence the name bestowed upon this strange, dark galaxy tickles me on several levels.